Humans
have developed throughout thousands of years, enough time for evolution. They
coped with the particular conditions of their lives to master their environment.
Thus humans survived (Darwin, 1859).
During
evolution there was the need for co-operation among the humans. Without it they
could hardly co-ordinate a joint effort, e.g. the hunt for strong or quick
animals. Later on uncoordinated utterances developed into patterned verbal
behaviour - speech (O'Neil 2004). Speech is generated by a set of rules -
language. The need and capability to communicate is not unique to humans. But
human language is unique in being a symbolic communication system that is
learned instead of biologically inherited. Symbols are abstract things that
have meaning given to them by the user. For instance, the English word
"cat" does not in any way physically resemble the animal it stands
for. All symbols have a material form but the meaning can not be discovered by
mere sensory examination of their forms.
The
flexibility of the human symbolic system is that is indefinitely flexible
(O'Neil 2004). Meaning is arbitrary assigned and it can be altered, and new
symbols can be created. Evidence of this property is given by the fact that new
words are invented daily and the meaning of old ones change. It allows us to
respond linguistically to major environmental, historical, and social changes.
As we life in a constantly changing world, we may adopt to these changes by
adjusting our language. There is no formal boundary to syntax or to semantics
we need to oblige. This world is an open system with many subjects, many
objectives and many goals. Being such complex nobody can ever tell what will
happen to the system in the next moment. Consequently humans employ informal
communication to describe and handle this open system.
When
looking on technology and interaction with technology we quickly recognise that
the nature of this system is fundamentally different. The semantic world of
technology is pretty limited - it only 'knows' what it was told by humans.
'Understanding' in this system is guaranteed only if both parties oblige the
same static rules. Advantages of having a such a system is that problems of
ambiguity is much less likely because there is one meaning to each symbol only,
not more and not less. Computers with its limited and inflexible syntax, e.g. a
particular order of attributes to a command, and with its limited and
inflexible semantics, e.g. only a set of ten commands, are closed systems
communicating formally with each other. Having particular abilities (Table 1
compares humans and machines), specialisation is advantageous. One particular
advantage might be used to fill a niche for application, an application that
supports humans in specific tasks.
|
Humans generally
better |
Machines
generally better |
|
- sense low level
stimuli |
- sense stimuli
outside human’s range |
|
- detect stimuli
in noisy background |
- count or measure
physical quantities |
|
- recognise
constant patterns in varying situations |
- store huge
quantities of data |
|
- sense unusual
and unexpected events |
- monitor
pre-specified events especially infrequent ones |
|
- remember principles
and strategies |
- make rapid and
consistent responses to IO signals |
|
- retrieve
pertinent details without a priori connection |
- recall
quantities of detailed info accurately |
|
- draw on
experience and adapt decisions to situation |
- process
quantitative data in pre-specified ways |
|
- select
alternatives if original approach fails |
- maintain
performance over extended period of time |
|
- reason
inductively: generalise from observation pre-programmed |
- reason
deductively: infer from general principle info accurately |
|
- act in
unanticipated emergencies and novel situations |
- exert great,
highly controlled physical force |
|
- apply
principles to solve varied problems |
|
|
- make subjective
evaluations simultaneously |
- perform several
activities simultaneously |
|
- develop new
solutions |
- maintain
operations under heavy information load |
|
- concentrate on
important tasks |
|
|
- adapt physical
response to changes in situation |
- maintain performance
over extended period of time |
Table 1: Advantages of humans and machines in
task performance (Levialdi)
Today computer
technology should support the car driver in critical situations by acting
autonomously from the human at the steering wheel. This is not only another
magnitude in computers supporting us but another quality too. If it was not
acknowledged before, the development from the industrial revolution on points
out: technology has gained an undeniable importance and influence. So has the
interface between us and the technology to manage the tasks it was made for. It is important to notice that it is
not the interface the user wants to master, it is the task!